We have previously demonstrated that high maternal intake of ascorbic acid determines a higher requirement for ascorbic acid in the offspring. Indirect evidence suggests that this effect is due to a higher rate of vitamin C catabolism. The aim of this proposal is to continue these studies by exploring the mechanism of this phenomenon during pregnancy and postnatally and, to define its general characteristics. Prenatally, the effect of high maternal intake of vitamin C will be explored by studying the mechanism of placental transfer of ascorbic acid, the influence of maternal intake of this vitamin on the activity of the ascorbic acid catabolic enzymes in the fetus and their ontogenesis. Postnatally, the consequences of a high maternal intake of vitamin C will be studied in the offspring to determine if the effect is transient or long lasting, and if the intensity of the effect is proportional to maternal intake. Further, we will determine the percent of progeny susceptible to scurvy while receiving the recommended daily intake of ascorbic acid. Different levels of high maternal intake of vitamin C will be administered for different lengths of time both during pre-pregnancy and pregnancy. "In vivo" studies will measure the rate of labelled CO2 excretion following injection of L(1-14C) Ascorbic Acid to the offspring. "In vitro" studies will be used to determine the levels of the ascorbic acid catabolic enzymes.